Fatal error: Uncaught Error: Call to undefined method mysqli_stmt::fetch_assoc() [duplicate]

Question

i'm trying to learn mysqli.

i get this error:

Fatal error: Uncaught Error: Call to undefined method mysqli_stmt::fetch_assoc() in C:\xampp\htdocs\bk2\login.php:14 Stack trace: #0 {main} thrown in C:\xampp\htdocs\bk2\login.php on line 14

and here is my db-conn.php:

 <?php
require('bk-config.php');

$conn = new mysqli($db_host, $db_user, $db_pass, $db_name);
if ($conn->connect_errno) {
    echo "Failed to connect to MySQL: (" . $conn->connect_errno . ") " . $conn->connect_error;
}

here is my login.php:

<?php
include 'db-conn.php';
$post_username = $_POST['post_username'];
$post_password = $_POST['post_password'];

$sql = "SELECT username, password FROM users WHERE username = ? AND password = ?";

$stmt = $conn->prepare($sql);
$stmt->bind_param("ss", $post_username, $post_password);
$stmt->execute();
$rows = $stmt->num_rows;

if($rows = 1){
  while ($row = $stmt->fetch_assoc()) {
    echo $row['username'];
  }
}

here is the form i have in the index.php:

<form class="px-4 py-3" action="login.php" method="post">
    <div class="form-group">
        <label>Username:</label>
        <input type="text" name="post_username" class="form-control" placeholder="Enter username">
        <label class="mt-2">Password:</label>
        <input type="password" name="post_password" class="form-control" placeholder="Password">
      </div>
      <button type="submit" class="btn btn-danger float-right">Login</button>
</form>

Where is the problem whit the fetch_assoc() in login.php?

Answer 1

You have 2 options.

You can process the resultset from the Statement object like this by binding the columns in the resultset to variables and then use those variables to output the data

<?php
include 'db-conn.php';
$post_username = $_POST['post_username'];
$post_password = $_POST['post_password'];

$sql = "SELECT username, password FROM users WHERE username = ? AND password = ?";

$stmt = $conn->prepare($sql);
$stmt->bind_param("ss", $post_username, $post_password);
$stmt->execute();

// bind variables to the resulted values
$stmt->bind_result($u, $p);

while ($row = $stmt->fetch()) {
    echo "Username = $u and Password = $p <br>";
}

Or you can convert the statements resultset to a mysqli_result object and do pretty much what you were doing.

<?php
include 'db-conn.php';
$post_username = $_POST['post_username'];
$post_password = $_POST['post_password'];

$sql = "SELECT username, password FROM users WHERE username = ? AND password = ?";

$stmt = $conn->prepare($sql);
$stmt->bind_param("ss", $post_username, $post_password);
$stmt->execute();

// convert to a result
$result = $stmt->get_result();

while ($row = $result->fetch_assoc()) {
    echo "Username = $row[username] and Password = $row[password] <br>";
}